I will try to keep it short as much as I can. First, the story isn't something unique or different, rather it is simple, but its execution is what makes it gripping. The plot could have been meatier especially when it comes to some characters like Yuri's or the old inmate's ones, but I think the drama can become longer then. I knew that there were two episodes extension, but I had never felt it dragging (comparing to other dramas). Acting..everyone is talking about the acting which is the highlight of this show. I don't know if it weren't Ji Sung and Uhm Ki Joon, this drama would have been that great. Both acted deliberately; never overacting nor underacting for even once.The chemistry between the characters is another highlight and the comic timing comes as a relief from all that tension. The music fits well and and it helps build up the tension and drag you into the mood. "I Love You Baby" was a sweet gesture and reflects the aim of the show and the motive behind our hero's journey. Rewatch value: I often don't find thrillers have high rewatch value as all clues unfold in the first time, but I can watch this once again just for the performances.